GLOSSARY. 585 



VARICES (Lat. varix, a dilated vein). The ridges or spinose lines which mark 



the former position of the mouth in certain univalve shells. 

 VASCULAR (Lat. vas, a vessel). Connected with the circulatory system. 

 VENTRAL (Lat. venter, the stomach). Eclating to the inferior surface of the 



body. 

 VERMES (Lat. vermis, a worm). Sometimes employed at the present day in 



the same, or very nearly the same, sense as Annuloida, or as Annuloida 



plus the A narthropoda. 



VERMIFORM (Lat. vermis, worm ; and forma, form). Worm-like. 

 VERTEBRA (Lat. verto, I turn). One of the bony segments of the vertebral 



column or backbone. 

 VERTEBRATA (Lat. vertebra, a bone of the back, from vertere, to turn). The 



division of the Animal Kingdom roughly characterised by the possession 



of a backbone. 



VESICLE (Lat. vesica, a bladder). A little sac or cyst. 

 VIBRACULA (Lat. vibro, I shake). Long filamentous appendages found in 



many Polyzoa. 



VIPERINA (Lat. vipera, a viper). A group of the Snakes. 

 VIVIPAROUS (Lat. vivus, alive ; and pario, I bring forth). Bringing forth 



young alive. 



WHORL. The spiral turn of a univalve shell. 



XIPHISTERNUM (Gr. ziphos, sword ; stemon, breast-bone). The inferior or 

 posterior segment of the sternum, corresponding with the " xiphoid carti- 

 lage" of human anatomy. 



XIPHOSURA (Gr. xiphos, a sword ; and oura, tail). An order of Crustacea, 

 comprising the Limuli or King-Crabs, characterised by their long sword- 

 like tails. 



ZEUGLODONTID.E (Gr. zeugle, a yoke ; odous, a tooth). An extinct family of 

 Cetaceans, in which the molar teeth are two-fanged and look as if com- 

 posed of two parts united by a neck. 



ZOOID (Gr. zoon, animal ; and eidos, like). The more or less completely in- 

 dependent organisms produced by gemmation or fission, whether these 

 remain attached to one another or are detached and set free. 



ZOOPHYTE (Gr. zoon, animal ; phuton, plant). Loosely applied to many 

 plant-like animals, such as Sponges, Corals, Sea-anemones, Sea- mats, &c. 



